Busy Tag AT Command Manual FW 2.0
This document describes the complete USB/serial AT command set exposed by Busy Tag firmware 2.0.
1. Introduction
Busy Tag is a smart status display. It is driven entirely over a USB CDC serial link using an AT command protocol. The device exposes a front RGB LED bar, an LCD display capable of showing PNG and animated GIF images, and internal ash storage with a FAT file system.
1.1 Key Features
- RGB LED bar - solid colors, custom multi-step patterns, and 25 built-in animations.
- LCD display - shows stored PNG and GIF images and solid color fills.
- USB CDC interface - complete AT command set for control and file transfer.
- Internal storage - FAT file system with wear leveling for images and data files.
- Temperature & diagnostics - internal die temperature, reset reasons, chip and bootloader info.
1.2 Hardware Specifications
2. Getting Started
2.1 USB Connection
Connect Busy Tag to a host with a USB cable. The device enumerates as a USB CDC serial port. Open it with any serial terminal.
2.2 Testing the Connection
> AT OK
2.3 Command Format
- Read / query: AT+<CMD>? or AT+<CMD>?
- Write / set: AT+<CMD>=<parameters>
- Action: AT+<CMD>
Every command line must terminate with \r\n (CR+LF). Commands are case-insensitive.
2.4 Response Format
- Data + success: a +<PREFIX>:<data> line followed by OK.
- Simple success: OK
- Error: ERROR :<code> - see Section 8.
- Prompt: > - the device is waiting for a data payload (file or pattern body).
- Event: +evn:<type>,<data> - asynchronous notification (e.g. image shown).
3. Device Information
> AT+GDN +DN : busytag -5 F83C0 OK > AT+GID +ID :240001ABC123 OK > AT+GFV +FV :2.0 OK > AT+GHV +HV :1.0 OK > AT+GESPV +ESPV : v5 .1.2 - dirty OK > AT+GTEMP +TEMP :42.5 OK
4. LED Control
The front RGB LED bar has 7 addressable positions, selected with a 7-bit bitmask (0-127). 127 (binary 1111111) selects all LEDs. Colors are given as RRGGBB hex.
4.1 Solid Color
> AT+SC=127 , FF0000 # all LEDs red OK > AT+SC=127 ,0000FF # all LEDs blue OK # The pins value is a 7 - bit mask , one bit per LED ( LED1 =1 , LED2 =2 , LED3 =4 , LED4 =8 , ...). > AT+SC=7 ,00FF00 # first three LEDs (1+2+4) green OK > AT+SC=8 , FFFFFF # fourth LED only ( bit 4) white OK > AT+SC? + SC :127 ,0000FF OK
4.2 Custom Patterns
A custom pattern is a sequence of steps, each: <pins>, <RRGGBB>,<speed>,<delay> where speed and delay are in milliseconds.
# Define a 2 - step pattern ( red , then green ) , each 100 ms with 500 ms hold > AT+CP=2 > +CP :127 , FF0000 ,100 ,500 +CP :127 ,00FF00 ,100 ,500 OK > AT+CP? +CP :127 , FF0000 ,100 ,500 +CP :127 ,00FF00 ,100 ,500 OK # Same 2 - step pattern set in a single line. # Steps use the + CP : prefix and are separated by a literal \r\n. > AT+CPD=+CP :127 , FF0000 ,100 ,500\ r \ n + CP :127 ,00FF00 ,100 ,500 OK > AT+PP=1,3 # play 3 times OK > AT+PP=1,255 # play forever OK > AT+PP=0,0 # stop OK
5. Display Control
5.1 Display Brightness
> AT+DB? +DB :75 OK > AT+DB =50 # set display brightness to 50% OK
5.2 Showing Images
Busy Tag displays PNG and GIF files stored in its file system.
> AT+GPL +PL:logo.png ,2048 +PL:animation.gif ,8192 OK > AT+SP=animation.gif OK +evn:SP,animation.gif > AT+SP? + SP:animation.gif OK
6. File Management
6.1 Storage Information
> AT+GFSS # free storage , bytes +FSS :1048576 OK > AT+GTSS # total storage , bytes (3 MB partition ) + TSS :3145728 OK
6.2 File Operations
> AT+GFL
+FL:config.json , json ,256
+FL: def.png , png ,1024
OK
# Upload a 12-byte file
> AT+UF=test.txt ,12
>
Hello World!
OK
# Read a file back
> AT+GF=config.json
+ GF:config.json ,256
{ ... file content ... }
> AT+DF=old_file.txt
OK
7. System & Reset Commands
7.1 Reset Reason Codes
AT+GLRR0 and AT+GLRR1 return the last reset reason for CPU core 0 and core 1 as a numeric code (+LRR0:<code> / +LRR1:<code>).
> AT+GLRR0 +LRR0:1 # core 0 last reset : power - on OK > AT+GLRR1 + LRR1:12 # core 1 last reset : software reset of the CPU OK
8. Error Codes
On failure the device responds with ERROR:<code>. The last error is also retrievable with AT+GLEC.
9. Complete Command Reference
10. Programming Example
All examples open the USB CDC serial port at 460800 baud, send each command terminated with \r\n, and read the +.../OK reply line
10.1 Python
import serial
ser = serial.Serial('COM3 ', 460800 , timeout=1)
def cmd(c):
ser.write((c + "\r\n").encode())
return ser.readline().decode().strip()
print(cmd("AT")) # OK
print(cmd("AT+GFV")) # +FV :2.0
cmd("AT+SC=127,0000FF") # all LEDs blue
cmd("AT+DB=60") # display brightness 60%
cmd("AT+SP=logo.png") # show an image
ser.close()
10.2 C#
using System;
using System.IO.Ports;
var port = new SerialPort ("COM3",460800) { NewLine = "\r\n", ReadTimeout = 1000 }; port . Open ();
string Cmd(string c)
{
port.WriteLine(c);
return port.ReadLine().Trim();
}
Console.WriteLine(Cmd("AT")); // OK
Console.WriteLine(Cmd("AT+ GFV")); // +FV :2.0
Cmd("AT+SC=127,0000FF"); // all LEDs blue
Cmd("AT+DB=60"); // display brightness 60%
Cmd("AT+SP=logo.png"); // show an image
port.Close();
10.3 Swift
Uses the ORSSerialPort library (macOS). Replies are delivered to the port's delegate; only the writes are shown here.
import ORSSerial
let port = ORSSerialPort (path: "/dev/tty.usbmodem1101")!
port.baudRate = 460800
port.open()
func cmd (_ c: String) {
port.send ((c + "\r\n").data(using: .utf8)!)
}
cmd("AT") // OK
cmd("AT+GFV") // +FV :2.0
cmd("AT+SC=127,0000FF") // all LEDs blue
cmd("AT+DB=60") // display brightness 60%
cmd("AT+SP=logo.png") // show an image
port.close()